Knowing they didn’t have their best stuff, Andy Murray and Novak Djokovic hit the shots they knew they could make. (AP)

We all know about winning ugly, but leave it to Andy Murray to show us how to win sarcastically.

The UK native is always wound a little more tightly at the World Tour Finals in London. Something about the crowd, the court and the competition never allows him to relax. Coming into this year’s edition of the event, Murray was just 11-11 at the ATP’s season-ender, and hadn’t advanced past the round-robin stage since 2012.

In 2016, Murray has one more reason to remain on edge: He’s in a one-on-one duel with Novak Djokovicfor the year-end No. 1 spot. On Wednesday, Murray faced one of the biggest obstacles to that goal in Kei Nishikori. Already in 2016, the two men had split five-set epics, and Nishikori had been sharp in his first match in London, a straight-set win over Stan Wawrinka.

Murray, in other words, had good reason to be anxious, and it showed. He started the match tentatively, hitting short, seemingly unable to loosen his arm and get on the offensive. It took just a few points for his repertoire of nods, smiles, rants, screams and thumbs up—all delivered with maximum sarcasm toward his player box—to commence. By the end of the first set, Murray had added a new move to his repertoire: the sardonic fist pump, which he flashed a few times after making unforced errors. His mood, it seemed, was contagious: By the third set, the normally placid Nishikori showed off his own sarcastic thumbs up after a Murray pass clipped the tape and bounced over his racquet.

Yet after three hours and 20 minutes of angst, anger and anxiety, Murray emerged the winner, 6-7 (9), 6-4, 6-4. It was his 21st straight victory, but this one was grueling rather than glittering. Each man made more errors than winners Murray’s first-serve percentage hovered around 50 and Nishikori was just two of 11 on break points. There were long rallies and a dramatic first-set tiebreaker, but it was a contest of opportunities lost rather than taken.

In that, it reminded me a lot of the previous night’s match between Djokovic and Milos Raonic. In both cases, the lower-ranked man seemed to be playing better and more proactive tennis. Nishikori and Raonic had multiple chances to grab control of the match, while Murray and Djokovic were mired in their own frustration and forced to react rather than attack. Yet in both cases, the younger player ended up getting away from his own game, struggling to close out important points at the net and—most crucial of all—choosing the wrong shot at the wrong time.

For Raonic, the down-the-line forehand was an issue; he often went to it too early, when there really wasn’t an opening. Nishikori’s problem was more obvious: Time and again, when he had an advantage in a rally, he chose to use his drop shot rather than finish with a putaway ground stroke. As Tennis Channel commentator Bret Haber said, Kei “took the racquet out of his own hands.” Nishikori would have been better off sticking with what he does best: drilling a ground stroke.

In the end, Murray and Djokovic won in similarly bloody-minded fashion. Knowing they were a little tight, and knowing they didn’t have their best stuff, they hit the shots they knew they could make. Their superior steadiness and defense meant that Nishikori and Raonic had to do something out of the ordinary to win. As we’ve seen over the years, the World Tour Finals is a tough place to do that. We knew Murray would be nervous for this match, but Nishikori wasn’t much looser.

There has been a lot of talk this week about the absence of Roger Federer and Rafael Nadal in London. It has been left to Murray and Djokovic, with their 2-0 records and their close wins over younger opponents, to remind us why the Big Four remains the game’s most exclusive and resilient club. They know how to survive, and it looks like they’re going to advance.